As silently as she had descended she climbed the stairs again. The door of Miss Girton’s room stood open, and she went in, crossed swiftly, and opened the casement windows. This room was on the opposite side of the house to the drawing-room, and just beneath the windows was a kind of shed with a sloping roof. As a schoolgirl, Patricia had often clambered through those windows and taken perilous toboggan-rides down the slates, saving herself from the drop by catching her heels in the gutter. Now she was bigger, and the stunt had no terrors for her.

Slithering swiftly over the sill she gathered up her skirt, held on for a second, and then let herself slide. Rotten as it was, the gutter stopped her as safely as it had ever done, in spite of her increased weight. Then she worked herself over the edge, let herself down as far as she could, and let herself fall the remaining five feet, landing lightly on the grass below.

She doubled round the house, and then she had a set-back, for the curtains of the drawing-room windows were drawn, and the windows themselves were closed. This had not been so when she came in. Returning from Lapping’s, she approached the house from the drawing-room side, and she could not have failed to notice anything so out of the ordinary, for Aunt Agatha verged on the cranky in her passion for fresh air and light even in the most unseasonable weather. Had the visitor, then, arrived after Patricia, or had the curtains been drawn for fear of her nosing round in the garden?

That, however, could be debated later. She stole up and examined both the French windows, but even from the outside she could see that they were fastened, and the hangings had been so carefully arranged that not even a hair’s breadth of the room was visible. She could have cried with vexation.

She meditated smashing a pane of glass and bursting in, but a moment’s reflection showed her the futility of that course. Simon Templar might have brought it off, but she did not feel so confident of her own power to force the pace. And with two of them against her, in spite of the automatic she might be tricked and over-powered. At a pinch she would have made the attempt, but the issue was too great to take such a chance when a man far more competent to deal with the matter was waiting to do his stuff if she could learn enough to show him where to make the raid. And the one certain thing in a labyrinth of mystery was that a man who visits somebody else’s house generally leaves it again sooner or later.

She looked around for a hiding place, and saw at once the summer-house in a corner of the garden. From there she could watch both the drawing-room windows and the front door—no observation post could have been better placed. She sprinted across to it. There was a window ideally placed, half overgrown with creeper, and through that she could see without being seen. Patricia settled down to her vigil.

It was about then that her name cropped up in the conversation which was taking place in the drawing-room, but that she could not know.

“One little pill—and such a little one!” remarked the man who was talking to Agatha Girton, and he placed the tiny white tablet carefully in the centre of the table. “You wouldn’t think it could make a grown woman sleep like a log for about six hours, would you? But that’s what it’ll do. Just put it in her coffee after dinner—it’ll dissolve in no time—and she’ll pass out within five minutes. Lay her out comfortably on the sofa, and I’ll collect her about eleven.”

He was a tall, sparsely-built man, and although they were alone he kept his soft hat pulled low down over his eyes and his coat collar was turned up to his chin so that only part of his face was visible.

“You can do your own murdering,” snapped Agatha Girton in a strained voice, but the man only laughed.